Usage:
3176 (2YG, 7LG) Truck Engines
Description of Change: A new cylinder head gasket is available. The new perforated core gasket replaces the former solid core gasket. Bond separation could occur in the former gasket, which could result in coolant leakage. The new perforated core gasket makes a mechanical bond between the metal core and the gasket paper. This will help prevent bond separation.
NOTE: The fire rings on the new perforated core cylinder head gasket are taped in place for assembly purposes. DO NOT REMOVE THE TAPE.
Adaptable To: The new 6I2009 Cylinder Head Gasket (perforated core) is a direct replacement for the former 9Y7044 Cylinder Head Gasket (solid core). The former gasket is canceled. Use the procedure that follows to install a new cylinder head gasket.
Installation Procedure
Use the appropriate Service Manual Modules as guides for this procedure.
1. Remove the cylinder head and former cylinder head gasket.
2. Inspect the cylinder head deck face and cylinder liner for wear/fretting under the fire ring. The wear is excessive if the wear can be felt with your fingernail. Resurface the cylinder head if necessary. The minimum permissible cylinder head thickness in 104.6 mm (4.118 in). Replace the cylinder liners as necessary. See the appropriate Specifications Module.
3. On 3176 Truck Engines 2YG1-Up and 7LG1-1400, measure the thread depth in the cylinder head bolt holes. The holes must be threaded to a minimum depth of 143.00 mm (5.630 in). If not, use a M16 X 2 bottom tap to increase the threaded depth to 143.00 mm (5.630 in).
4. Measure and record cylinder liner projection. See the appropriate Systems Operation, Testing And Adjusting Module.
5. Put a new 6I2009 Cylinder Head Gasket (perforated core) in position of the block. DO NOT REMOVE THE TAPE THAT HOLDS THE FIRE RINGS IN PLACE.
6. Install one guide stud (modified 8T1485 Bolt) in each end of the block.
7. Use the guide studs to guide the cylinder head into position on the block without disturbing the cylinder head gasket.
8. Put a light coat of 6V4876 Molykote Paste Lubricant on the cylinder head bolt threads and under side of the bolt heads. Also put the lubricant of the cylinder head bolt washers.
9. Tighten the cylinder head bolts as shown in the appropriate Disassembly And Assembly Module.